Power excavating device



Nov. 27, 1962 c. w. PEWTHERS 3,065,557

POWER EXCAVATING DEVICE Filed July 1, 1960 4 Sheets-Sheet 1 INVENTOR.Wu. F QJJQ Mi QM 1 Nov. 27, 1962 Filed July 1, 1960 c. w. PEWT/HERSPOWER EXCAVATING DEVICE 4 Sheets-Sheet 2 Nov. 27, 1962 c. w. PEWTHERS3,065,557

POWER EXCAVATING DEVICE Filed July 1, 1960 4 Sheets-Sheet 3 (flaw/e1 WPew/hens" INVENT OR.

mew/pm? ATTORNEY) 1962 c. w. PEWTHERS POWER EXCAVATING DEVICE 4Sheets-Sheet 4 Filed July 1, 1960 W a, Z 6 I r .i H w NH" l 0 H I m 4 0diw 7 1 WW .J /aw w W 1 9 3 w( m J H A m 2 J y m M Z 4 a u m tats Thepresent invention relates to improvements in power excavating devices,and, more particularly, relates to improvements in power impact hammersand movable teeth mounted at the leading end of earth excavatingdevices.

Power driven excavating devices, such as shovels, front end loaderbuckets, shovel buckets, clam shells, back hoe buckets, and other typesof shoveling and devices of the power type are in widespread use. Inmany instances, however, such excavating devices are ineffectual andsubstantially useless, for example, in digging in hard materials, suchas frozen ground, frost lines, concrete surfaces, and hard rockformations such as caliche, limestone, iron ore, coral, and the like. Onthe other hand, when the earth is heavy-bodied and soggy and sticky, themovement of the bucket or shovel through the earth ofi'ers a viscousresistance, so that an extremely large amount of power is required topass the shovel or bucket into and through the earth.

These problems are not satisfactorily solved by the use of bigger orlarger equipment because the larger equipment cannot be used because ofits bulky size, difficulties in transportation and cannot be used forwork in close quarters. In addition, the provision of such largerequipment substantially increases the initial and operating costs.

While numerous movable teeth and power arrangements for moving the teethhave been proposed in the past for power type bucket and shovels, to myknowledge none has been successful to the extent that they have beenaccepted by the trade. This is probably due to one or more of thefollowing. The prior devices are complicated, most of them do not havethe required power to deliver the required impact, most of them are solarge that they cannot readily be secured to power buckets and shovelswithout materially interfering with their operation otherwise, and mostof these prior proposed devices require several power impact hammers,ordinarily one impact hammer for each movable tooth and require anoutside power source, such as an air compressor.

The present invention is directed to a power excavating device whichovercomes the disadvantages of the previously proposed arrangementsmentioned above and which provides a very simple arrangement andassembly for providing tremendous impacting power by a relatively smalland simple arrangement, which does not materially increase the size orbulk of the excavating device or appreciably reduce bucket capacity andyet enables it to dig through extremely hard formations and formationsproviding viscous resistance.

It is therefore an object of the present invention to provide a powerexcavating device which includes power driven impact teeth by which thedevice will readily and easily dig through. extremely hard formations orformations offering viscous resistance which is relatively small,simple, compact and which does not materially increase the bulk of theexcavating device or materially interfere with the normal functions ofthe excavating device.

Yet a further object of the present invention is the provision of animproved means for removably mounting teeth on the leading edge of apower excavating device by a very simple and ruggedly-efiicientarrangement.

Yet a further object of the present invention is the provision of animpacting assembly to a power shovel or bucket 3,65,557 Patented Nov.27, 1962 in which movable teeth are removably held in position at theforward end of the bucket or shovel and by which the impact to the teethis provided by one or more impacting hammers impacting a common anvilshaft which in turn impacts a large number of teeth with respect to theimpacting hammers.

Yet a further object of the present invention is the provision of apower bucket or shovel having power driven impacting teeth adjacent itsleading edge which are driven hydraulically by the hydraulic system ofthe power excavating machinery to which the power bucket or shovel isconnected, for example, tractors and the like.

Yet a further object of the present invention is the provision of animproved power excavating device which is of relatively small size bywhich tremendous digging or penetrating power is provided forpenetrating extremely hard formations or formations offering viscousresistance.

Yet a further object of the present invention is the provision ofmounting arrangements which removably mounts teeth on the leading end ofa power shovel or bucket and in which the mounting means serves as ahammer member for the teeth and an anvil member for the impactingdevice.

Yet a further object of the present invention is the provision of apower bucket or shovel provided with impacting teeth which is ofrelatively small size, simple in design, ruggedly efiicient in use andwhich will penetrate extremely hard formations and formations having aviscous resistance to digging.

Yet a further object of the present invention is the provi sion of apower shovel or bucket which includes movablymounted bucket teeth andone or more hydraulic impact hammers driving the teeth in which theirhousings are carried by the bottom wall and extend through the back wallor a portion thereof of the shovel or bucket with the hydraulic motorsand lines being located behind the back wall or portion thereof andabove the bottom wall thereby providing minimum interference with normaldigging of the shovel or bucket.

Other and further objects, features and advantages of the invention willbe apparent from the following description of presently-preferredembodiments of the invention, given for the purpose of disclosure, andtaken in conjunction with the accompanying drawings, in which likecharacter references designate like parts throughout the several views,and where FIGURE 1 is a perspective view illustrating a power excavatingor digging device according to the invention, FIGURE 2 is a perspectiveview illustrating the bottom of a bucket tooth of FIGURE 1,

FIGURE 3 is a fragmentary, exploded view, illustrating the connectingassembly of FIGURE 1 connecting the bucket teeth to the leading edge ofthe power bucket,

FIGURE 4 is a side elevational view, partly in section, illustrating thepower excavating or digging device of FIGURE 1 and taken along line '44of FIGURE 5,

FIGURE 5 is a front elevational view of the power excavating or diggingdevice of FIGURE 4,

FIGURE 6 is a top sectional view illustrating a modified powerexcavating or digging device according to the invention and taken alongline 6-6 of FIGURE 7,

FIGURE 7 is a cross-sectional view taken along the line 77 of FIGURE 6,

FIGURE 8 is a side view, mostly in section, illustrating a highlysatisfactory impact hammer for mounting in the excavating and diggingdevices of FIGURES 1-7, and

FIGURE 9 is a hydraulic flow circuit satisfactory for use in providinghydraulic power to the hydraulic motor of the impact hammer illustratedin the preceding figures.

Referring now to the drawings, and particularly to FIG- URE 1, a powerexcavating device, such as the bucket or shovel, generally designated bythe reference numeral 16, is provided which is of the back hoe type.That is, it is the type of shovel which is utilized in digging in abackward direction, that is a direction toward the machine, such as atractor, to which the bucket is connected.

The power bucket 19 may take any desired shape and, ordinarily, includesthe bottom 12, the sides 14, the back 16, and suitable bracket orconnecting elements 18 by which the power bucket 10 is connected tosuitable power driven linkage, not shown, connected to suitable powerexcavating machinery, for example, a tractor (not shown) in theconventional manner.

Since the particular shape or configuration of the power bucket as suchdoes not constitute the present invention and the principles of theinvention may be applied to any power bucket or shovel, no furtherdescription thereof is deemed necessary or appropriate. As will beapparent later, however, the power impact means is combined with thepower bucket in such a manner to provide minimum interference with thenormal excavating function of the bucket 10 and to provide a minimum ofloss in bucket capacity.

In accordance with the present invention the movable bucket teeth ordigging elements, generally indicated by the numeral 20, are secured tothe leading end 22 of the power bucket 16 by a connecting assemblyincluding a generally transversely-extending slot 24 as best seen inFIGURE 4, formed by the front and back walls 26 and 28, the upper wall36 and the bottom wall 31..

. In order to provide a relatively sharp forward edge 32 and stillprovide sufficient strength to the teeth 20, they are formed generally,when viewed in longitudinal section, in a triangular shape. Thus,suflicient strength is provided adjacent the leading portions 32 of theteeth 20 and they are of sufficiently large size to accommodate theslots 24' (FIGURE 2) which form a continuation of the slot 24 whenassembled. As shown in FIGURES 3 and 4, an anvil bar 34 extends acrossand adjacent the leading end 22 of the power bucket 10 through the slots24 and 24'. The anvil bar 34 is prevented from moving out of the slot 24by contacting the inner side of the side wall 37 and at the other end bythe removable side wall 36. Thus, the anvil bar 34 is secured in theslot 24 and through the slots 24' in the teeth '20 and is permittedlimited reciprocating motion generally in a backward and forwarddirection of the teeth 20, the plate 36 being removably secured to theforward portion of one side 14 of the bucket 10 such as by the nuts andbolts 38 (FIGURE so that the anvil bar 34 may be removed to release theteeth 20.

Each of the teeth 20 are provided with the longitudinally-extendingslots 29 on each side formed by the longitudinally-extending flanges 31'and 33 in which the longitudinally-extending flanges 35 at the sides ofthe forward end 22 slidably fit. Thus, a plurality of digging teeth 20is secured to the leading digging end 22 of the bucket by simply placingthese teeth in position as shown in FIG- URE l and sliding the anvil bar34 through the openings 24 provided therein. If desired, the leading end22 may be formed separately from the bucket 10 and secured thereto asshown or formed in the leading end of the bucket.

Advantageously the arrangement described for mounting a plurality of theteeth 20 serves to impact or move the teeth 20 simultaneously and, ifdesired, by a single impacting hammer such as generally designated bythe reference numeral 40.

The details of a highly effective impact hammer 40 are illustrated inFIGURE 8. A housing 39 is provided which includes the motor housing 41and the cylindrical shaft housing 43. Motor housing '41 carries thehydraulic motor 94 which is provided with the output shaft 42 which isconnected by the flexible coupling 44 to the combined rotor and coupling46, such as by the splines 48, so that rotation is transmitted from theoutput shaft 42 through the flexible coupling 44 to the combined rotorand coupling 46.

An antifriction assembly generally designated by the reference numeral56 is provided adjacent the inner end of the combined rotor and coupling'46 which, of course, reduces friction and particularly any thrustaction imparted to the combined rotor and coupling 46.

A counterbore 52 is provided in the outer end of the combined rotor andcoupling 46 which is provided with a plurality of axially-extendinggrooves 54 for reception of the inner end 56 of the impact shaft 58, theinner end of which is provided with the complementary set of mating andaxially-extending grooves 60 in which the antifriction elements such asthe balls 62 are provided. Thus, rotation is imparted from the combinedrotor and coupling 46 to the impact shaft 53 but yet limited axialmovement of the impact shaft 58 is permitted with respect to the bushingand rotor 46. 1

The impact shaft 58 is provided with an annular enlargement 64intermediate its ends and includes the inwardly facing annular shoulder66 which serves as a stop for the compression spring 68 or energystoring means disposed about the impact shaft 58, the other end of whichstops against the outwardly facing annular shoulder 70 of the combinedrotor and coupling 46.

The outwardly-facing portion of the enlarged intermediate section 64 ofthe impact shaft 58 is provided with a suitable rotary jarmechanism'which includes a single cam face 72 which is in the form of.an annular inclined cam face or helix and includes a single abruptaxiallyaligned shoulder surface 74 which permits abrupt axial travel ofthe shaft in an outward direction in response to the action of the coilspring 68 or energy storing means.

The impact shaft 58 and a portion of the combined rotor and coupling 46are disposed within a generally cylindrically-shaped shaft housingmember 43 which, preferably, is releasably secured to the motor housingmember 41, such as by threading as illustrated, so that the variousparts may readily and easily be assembled or replaced and repaired.

The shaft housing member 43 includes the nose cone 45 which, preferably,is releasably secured to the body member 43, such as by threading asillustrated, again for the purpose of ease of assembly and makingrepairs and replacement of parts.

The nose cone 45 is provided with a cooperating or mating cam face 76which is complementary to the cam face or surface '72 and, accordingly,is in the form of an annular inclined cam face or helical face which isprovided with the single, abrupt, axially-aligned shoulder surface 78.

The nose cone 45 is provided with suitable seals 80 adjacent itsthreaded portion and is provided with the seal 82 at its outer inner endthrough which the outer end 84 of the impact shaft 58 extends.

Thus, actuation of the hydraulic motor 94 rotates the power output shaft42 and the impact shaft 58 through the flexible coupling 48 and combinedrotor and coupling 46, including the antifriction elements 60, wherebythe cam surfaces 72 and 76 alternately compress and release thecompression spring 68 or energy storing means thereby providing anabrupt impacting movement of the impact shaft 58 in an outer directiononly.

At the present time a large number of excavating devices, such as powerbuckets and shovels, are actuated by machinery including a hydraulicsystem. The impact hammers described and shown advantageously use thehydraulic system of the machinery, for example, a tractor to which thepower bucket or shovel is connected.

Referring now to FIGURE 9, a typical and satisfactory hydraulic systemis illustrated which includes a suitable hydraulic pump 88 which isconnected by the hydraulic line 90 through the regulating valve 92 tothe hydraulic motor 94. A hydraulic return line 96 returns hydraulicliquid from the motor 94 into the hydraulic reservoir 98 which includesthe hydraulic flow line 100 leading to the hydraulic pump 88.

In present day equipment, the hydraulic controls are locatedconveniently to the operator, for example the controls for manipulatingthe power bucket, as well as the control valve 92. Thus, the impacthammer is controlled'as desired by the operator at the control positionof the machinery to which the power bucket or shovel is connected, andadvantageously operated as desired,

The impact hammer illustrated in FIGURES and 6 is particularly suitedand adapted for use in power shovels and buckets according to thepresent invention in view of the fact that it occupies very small space,delivers tremendous power and impacts of an order sufficient to providea highly practicable and workable tool and is readily and easilyoperated from the operator controls with a minimum of alteration oradaptation of the machinery involved.

Referring again to FIGURE 4, the impact hammer 40 is mounted on orclosely adjacent the bottom wall 12 of the power bucket It} with thehammer end 84 extending out of the nose cone 45 and in engagement withthe anvil bar 34 so that actuation of the impact hammer 40 causes thehammer 34 to hammer the anvil bar 34 which, in turn, hammers the teeth2%.

As illustrated, the body of the impact hammer is preferably disposedcompletely Within the outer confines of the power bucket or shovel It awell 101 being provided at the central portion of the back 16 in whichthe hydraulic motor 94 is mounted. Preferably, the motor housing 94 isconnected to the back side of the wall 192 of the well 101. In order toprovide a smooth inner bottom andto prevent dirt, liquids and the likefrom becoming entrapped under and around the body of the impact hammer40, a false bottom 104 is provided as shown with a slot 165 (FIGURE 1)to receive the impact hammer 44). If desired, the motor may be mountedbehind the back wall 16, it only being necessary that the motor 94 bemounted at the rearward portion of the bucket and behind a wall portionto preferably prevent earth and the like from contacting the motor 94and hydraulic lines 90 and S6. Thus, the combined bucket, impactingdevice and teeth mounting arrangement advantageously provide a minimumof interference with normal excavating or digging operations, yetprovide a highly effective impacting arrangement for a power bucket ordigging device.

Thus, upon contacting a particular formation or surface through which itis desired to dig, the operator needs merely to position the powerbucket or shovel 10 to engage the surface in the usual manner fordigging, and then actuate the impact hammer 40 which in turn impacts anddrives the digging elements 20 in a forward direction.

As previously mentioned, while for many uses and applications only asingle impact hammer 40 is required to provide the necessary impactingforce through the mounting arrangement illustrated, more than one suchimpacting hammer may be utilized, if desired, such an arrangement beingillustrated in FIGURES 6 and 7, to which reference is now made. In thesefigures, the refence letter a is added to those parts corresponding tothose of FIGURES 1-5, 7 and 8. Essentially, as shown in FIGURE 6, thesame arrangement is utilized as in FIGURES 15, inclusive, except thatthe power bucket or shovel 10a is considerably wider than thatillustrated in FIGURES 1-5, inclusive, and includes additional and moreWidely spaced digging elements or teeth 20w. In

this arrangement, two impact hammers 40a impact one or more anvil shafts34a, the hydraulic motors 94a of which are connected by suitablehydraulic lines, not shown, to the hydraulic system of the machinery towhich the power bucket Illa is attached, such as a tractor.

The remaining parts, structural arrangement and mode of operation arethe same as that described in connection With FIGURES 1-5, 7 and 8,except that a plurality of impact hammer units 4% and one or more anvilshafts 34a are used instead of a single impact unit 40. Accordingly, nofurther detailed description of this modification is deemed necessary orappropriate.

As previously mentioned, power excavating and digging devices accordingto the present invention have been highly satisfactory in use in that avery small device is, in effect, made to do a very large job whichcannot be done by a large device because of the latters size, difiicultyof transportation, inability to use in close quarters, extreme expenseand the like. In addition, a power device according to the presentinvention has been highly satisfactory in penetrating extremely hardmaterials and formations for example concrete, caliche, iron ore, coral,limestone, frost lines and various other hard ground formations whichheretofore could not successfully be penetrated by previous powerbuckets and shovels.

The mounting arrangement for the power buckets and shovels can, ofcourse, be used with other type impacting hammers. It is highlyadvantageous and particularly suited to use with a hydraulic impacthammer of the type described and illustrated in view of the compact sizeand ability to combine it with a power bucket or digging device asmentioned, the impact power generated, and the ability of providingvarying rates of impact under various conditions with a minimum loss ofpower.

The present invention, therefore, is well suited and adapted to attainthe ends and objects and has the advantages and features mentioned aswell as others inherent therein.

While presently preferred embodiments of the invention andrepresentative uses and applications have ban given for the purpose ofdisclosure, other uses and applications and changes in details ofconstruction and arrangement of parts may be made which are within thespirit of the invention as defined by the scope of the appended claims.

What is claimed is:

I. An excavating bucket adapted for connection to a power drivenexcavating apparatusand having side, bottom and back walls defining achamber with an open front portion for receipt of earth and the likethrough said portion into said chamber, a plurality of bucket teethcarried by the bottom wall and projecting forwardly in advance of theleading edge of the bottom wall, an anvil member, each bucket toothhaving an anvil receiving slot for detachably holding the teeth to saidanvil, means mounting the anvil member relative to the bottom wall forlimited movement in a direction projecting the bucket teeth forwardly ofthe leading edge of the bottom wall, a housing carried by the bottomwall and extending rearwardly through a portion of the back wall, arotary jar mechanism in the housing including an impact hammer spacedfrom the anvil member for impacting the anvil member in the forwarddirection of the bucket teeth, a rotatable hydraulic motor driving therotary jar mechanism connected to the housing and disposed rearwardly ofsaid portion of the back wall and above the bottom wall, and means onthe motor disposed rearwardly of said portion of the back wall and abovethe bottom wall for connection to a source of hydraulic pressure forrotating the rotary jar mechanism.

2. In combination with an excavating bucket; a wall adapted for receiptof earth and the like, a tooth receiving structure carried forwardly ofsaid wall, a plurality of teeth, each of said teeth being slidably anddetachably carried by said structure for vibratory movement with respectthereto, an impact means positioned adjacent said teeth for impactingsaid teeth forwardly, a rotary jar mechanism carried by said Wall andpositioned rearwardly of said teeth and including an impact hammerspaced from said impact means, an energy storing means for driving saidimpact hammer forwardly against said impact means, and a rotaryhydraulic motor drivingly connected to said 7 rotary jar mechanism foractuating the energy storing means.

3. In combination with an excavating bucket; a wall adapted for receiptof earth and the like, a tooth receiving structure carried forwardly ofsaid wall, a plurality of teeth, each of said teeth being slidably anddetachably carried by said structure for vibratory movement with respectthereto, an impact means positioned adjacent said teeth for impactingsaid teeth forwardly, a retractable impact hammer, an energy storingmeans normally driving said impact hammer forwardly against said impactmeans, a rotary jar mechanism carried by said wall and positionedrearwardly of said teeth and connected to said retractable impact hammerfor retracting said hammer from the impact means, and a rotary hydraulicmotor drivingly connected to the rotary jar mechanism for alternatinglyactuating and releasing the energy storing means and impact hammer.

4. An excavating bucket adapted for connection to a power drivenexcavating apparatus and having side, bottom and back walls defining achamber with an open front portion for receipt of earth and the like, aplurality of bucket teeth, each of said teeth being slidably carried bythe bottom wall and projecting forwardly in advance of the leading edgeof the bottom wall, an anvil member carried by the bottom wall andpositioned adjacent said teeth for impacting said teeth forwardly, ahousing carried by the bucket, a rotary jar mechanism in the housingincluding a retractable hammer adapted to be spaced from the anvilmember for impacting the anvil and teeth in the forward direction, andspring means positioned coaxially with and normally driving the hammerforwardly, and a rotatable hydraulic motor connected to and driving therotary jar mechanism.

5. In combination with an excavating bucket; a wall adapted for receiptof earth and the like, a plurality of bucket teeth slidably carried bysaid wall and projecting forwardly in advance of the leading edge of thewall, an impact means positioned adjacent said teeth for impacting saidteeth forwardly, said impact means detachably connecting the teeth tosaid wall, a rotary jar mechanism carried by the bucket and positionedrearwardly of said teeth and including a retractable impact hammer, saidhammer spaced from the impact means when retracted, an energy storingmeans for driving said impact hammer forwardly against said impactmeans, and a rotary hydraulic motor drivingly connected to said rotaryjar mechanism for actuating the energy storing means.

6. In combination with an excavating bucket; a wall adapted for receiptof earth and the like, a tooth connecting assembly carried by the wall,said assembly having a plurality of tooth receiving slots for receivingteeth, a bucket tooth slidably carried in each of said slots andprojecting forwardly in advance of the leading edge of the wall, animpact receiving means detachably connected to each of the teeth andsupported by the assembly for limited movement in a direction forprojecting the bucket teeth forwardly of the leading edge of the wall, ahousing carried by the bucket, a rotary jar mechanism in the housingincluding a retractable hammer adapted to be spaced from the impactreceiving means for providing impact to the teeth in the forwarddirection and including an energy storing means for driving said impacthammer forwardly, and a rotatable hydraulic motor in the housing andconnected to and driving the rotary jar mechanism.

References Cited in the file of this patent UNITED STATES PATENTS1,041,569 Bade Oct. 15, 1912 2,191,608 Coates Feb. 27, 1940 2,228,445 DeVelbiss Jan. 14, 1941 2,408,484 Schwarzkopf Oct. 1, 1946 2,905,168 HenrySept. 22, 1959 FOREIGN PATENTS 894,880 France Mar. 20, 1944 922,519Germany Jan. 17, 1955

